Electric rivet heater



Apr. 24, 1923.

w. s. JOHNSON ET AL ELECTRIC nrvm HEATER Filednug. 17. 1920 Patented Apr. 24, 1923.

UNITED STATES PATENT OFFICE.

WILLIAM 8. JOHNSON AND JOHN W. BERWICK, PENNSYLVANIA, YA S'SIGNORS T0 AMERICAN CAB. AND FOUNDRY COMPANY, 0F ST. LOUIS,

IISSOUBI, A CORPOBATIOILOF NEW JERSEY.

ELECTRIC EIVET HEATER.

Application lcd August 17, 1920. Serial No. 404,178.

'To Be it known that'we,'Wn.mAu S. JormsoN and JOHN W. Snarrna, residingat Berwick, county of Columbia, and tate of 6 Pe lvania, and being citizens of the United States, have invented certain new and useful l'ixiprovements in an Electric Rivet Heater, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to. which it appertains to malte and to use the same, reference bein had to thaiE accompanying drawn whlch illustrate the preferred form o t e invention; though it is to be under stood that the inventionis not limited to the exact details of construction shown and described, as it is obvious that various modications thereof within the scope of the `claims will occur to persons skilled in the 2 art.

`In said drawings:

Figure 1 is a broken front elevation of our improved electric rivet heater with a primary coil and a secondary coil shown in section;

Figure 2 is an end elevation of our device;

Figure 3 is a fragmentary horizontal section taken on the line 3 3 of Fig. 1;

Figure 4 is a view of the insulation placed between the primary and seconda coils;

Figure 5 is a view in side elevation of the secondary coil detached from the core and rovided with terminal electrodes or blocks esigned to receive steeple head rivets of diil'erent lengths without an excessive movement of the terminal blocks; and

Figure 6 is an end view of a modified form of terminal block designed to accomplish the same urpose.

It iisi the object of our invention to provide an improved electric rivet heater wherein the primary and secondary coils alternate 'on the core and the secondary coil and the insulation form a chamber, open on but one side, to receive the rivet for heating.

It is also an object of our invention to provide an improved heater that may be readily shifted by means of a crane or derrick and which has very little projecting bew yond the line of the frame and liable to damage by contact with other objects while the heater is being moved.

Other objects and advantages will be ap parent from the description of the drawings in which 1 and 2 designate flanged preed metal side members or uprights joined by cross piece 3, secured to the side members in any suitable manner, as by riveting. Secured to the tops of the side members 1 and 2 are an lebar members, as member 4 in Fig. 1, avm? one flange secured to the top flanges o the side members and the other flange extending upwardly therefrom. Mounted between the members 4 is the rectangular laminated core 5, the members 4 being forced into engagement with the core 5 by the bolts 6 which pass through the members 4 and beneath the core. 5 and serve'to keep the laminations of the core tightly pressed together. The end rtions of the core 5 are engaged b the ang e bars 7 and 8, as shown in Fig. 3, t e angle bars being held in engagement with the core 5, so as to hold the laminations of the core together,l by means of bolts 9 and 10 which pass outside of the re, the bolts 10 also serving to secure the an le bars 7 and 8 to the angle bars 4. The U-s aped angle bar 'member 11 and the hoisting loo s 12 have their ends adjacent to the ang e bars 7 and 8 and secured thereto by the bolts 9 and 10,

Surrounding the upper horizontal ortion ofthe core 5 are the alternately` placed primary and seconda coils 13 and 14 with separators or insulation -16h between each pair of coils. The rimary coils consist of unit coils of the desired number of turns of wire wound on a form and suitably wrapped and insulated before being placedl on the core. The secondary com rises a number of bare copper strips joine by arc welding, to the copper blocks 17 which serve as the electrodes and between which the rivet is placed for heating. Between the coils and the core insulating strips 15 are placed.

The upper block 17 of each secondary coil v14 is secured to the angle-bar 11 by the screw threaded rod 18, the block being adjustable to dierent positions with respect to the4 bar 11 by means of the nuts 19. To each of the lower blocks 17 is secured a lug 20 to which one end of a rod 21 Y 26 confined between a pin 27 passed through the rod 21 and a bracket 28 secured to the cross piece 3.

The separators 16 are designed to insulate with respect to both heat and elevtricity and may com )rise` as shown in Fig. 4, a rectangular bod with a central rectangular opening andyslots extending from the opening to the outer faces of the body. Itmay be conveniently constructed by forniing rectangles from sheets of a material having good heat insulating qualities as well as being an electrical insulator and joining two Such rectangles by spacing or corner pieces of the same material. The separators serve to electrically insulate the coils from each other and revent the radiation of heat from the secon ary coil or heated rivet to thc primary coil and with the blocks 17 of Athe secondary coils and the insulated core form a chamber, o en on one side only, to receive the rivet while it is being heated, thus preventing much of the loss of heat by the rivet by radiation to the coils and core and the los that occurs where the rivet is exposed to air currents from all directions resulting in a device that is more efficient and not subjected to a variation in its operation by varyin air conditions.

Secured to t e front flanges of the side members 1 and 2 adjacent their tops is the rivet trough 29 and mounted on an insulating base secured to the'angle bar 11- is the main control switch 30.

In Fig. 5 there is shown an 'upper terminal block 17* having the front portion ot the rivet en agi surface cut away so as to form an L-s ape block providing engaging surfaces 17c and 17, lying in different planes, with the engaging surface 17 beow and in back of the surface 17d. This construction provides rivet engaging surfaces at different distances from the lower terminal block and permits of a greater range in the length of the rivets that can be heated in one machine without having an excessive movement of the blocks. The same results may also be obtained as shown in Fig. 6 where both the upper and lower terminal blocks are partly cut away at one side providin the rivet engaging surfaces 17 at one si e of and closer together than the surfaces 17. The lower terminal blocks 17", as shown in Fi 5, is provided with openings 17 extendln(7 through the block and counterbored at the top to provide a contact surface for enga ing Steeple head rivets, the openings inI t e block furnishing discharge passages for any scale that may be deposited on the contact surface and preventing the point of the rivet head being urned during the heating.

What we claim is:

1. In an electric rivet heater, a core, a coil on said core and means mounted on said core and cooperating with said coil to form a chamber to receive the rivet.

2. In an electric rivet heater, a core, a coil Vsurrounding said core 4and insulation adjacoils and said core insulation to receive the l rivets.

5. In an electric rivet heater, an insulated core, a plurality of primary coils surrounding said core, a secondary coil between said primary coilselectrodes on said secondary coil adapted to cooperate to hold a rivet and insulation between said rima and secondary coils forming a cham r wit said electrodes and core insulation.

6. In an electric rivet heater a frame, a core carried by said frame, surrounding said core and a U-shaped member carried by said frame and supporting said coils.

7. In an electric rivet heater a frame, a core carried by said frame, coi surroundingsaid core, a control switch and a sup; port for said coils and said switch carried by the frame.

8.. In an electric rivet heater, u frame, a core carried by said frame, means securing said core to said frame and hoisting loops secured to said securing means.

9. In an electric rivet heater, a frame, a.

core carried by said frame, means securing "105 said core to said frame, coils on said re, a

support for said coils, hoisting loops and means joining said. support and hoisting loops to said securing means.

10. In an electric rivet heater, a secondary coil comprising flexible copper strips and solid rivet engaging copper electrodes welded to said strips.

11. In an electric rivet heater, a secondary coil having electrodes, one of said electrodes being shaped toprovide independent rivet engaging surfaces.

12. In an electric rivet heater, a secondary coil having one terminal rovided with contact surfaces lying in di erent planes and a second terminal on said coil having distinct contact surfaces adapted to cooperate with the surfaces of the other terminal.

13. In an electric rivet heater, a secondary coil having terminals thereon, each of said terminals having a plurality of distinct contact surfaces.

14. In an electric rivet heater, a secondary 15. In an electric rivet heater, a secondary coil electrode having rivet engaging surfaces lying in different planes.

16. In an electric rivet heater, a secondary 5 coil electrode having a plurality of parallel rivet engaging surfaces.

17. In an electric rivet heater, a secondary coil electrode having openings therein, the walls of which serve as rivet engaging open-f 10 ings. A

18. In an electric rivet heater, a secondary coil having one terminal provided with a plurality of contact surfaces and a second electrode on said coil having perforations therein the walls of which serve as contact l5 surfaces and cooperate with the surfaces of the first electrode to hold the rivet.

In witness whereof' we have hereunto set our hands in the presence of two witnesses.

WILLIAM S. JOHNSON.V

JOHN W. SHEFFER. Witnesses:

H. F. TRAUGH, FRED A. HOFFMAN. 

